Client applications use functions from the OLE API to inform the client library, OLECLI.DLL, that a user wants to perform an operation on an object. The client library uses DDE messages to communicate with the server library, OLESVR.DLL. The server library is responsible for starting and stopping the server application, directing the interaction with the server's callback functions, and maintaining communication with the client library.
When a server application modifies an embedded object, the server notifies the server library of changes. The server library then notifies the client library, and the client library calls back to the client application, informing it that the changes have occurred. Typically, the client application then forces a repaint of the embedded object in the document file. If the server changes a linked object, the server library notifies the client library that the object has changed and should be redrawn.